14 



FLOWERS. SEED PRODUCTION 



to attract insects by the color and perhaps to form a case for 



-oectar, which will reward insects for their visits. 



If the flower does not contain both of the essential organs- 



stamens and pistils it is called an imperfect flower (Fig. 7). 



In such cases the other set of organs is found in other flowers on 



the same plant as in 

 corn, or on other indi- 

 vidual plants, as in pop- 

 lars. Monecious plants, 

 as corn, are those in 

 which the staminate 

 flowers and pistillate 

 flowers are both on the 

 same plant. Diecious 

 plants are those in 

 which the staminate 

 and the pistillateflowers 

 are on different plants, 

 as in the cottonwood 

 and poplar trees. 



Flowers may be 

 borne singly as in case 

 of the poppy (Fig. 6), 

 in heads as in the sun- 

 flower (Figs. 8 and 12), 

 in spikes (Fig. 11) and 

 in many other forms of 

 clusters. 



Pollination. In per- 

 fect flowers the pollen 

 found in the stamens 



.Flo. 7.-Ear of corn in full silk and ready to be maV fal | directlv U P n 

 pollinized. There is one silk from each kernel and each the pistil. 



must receive a pollen grain, from some corn tassel, which 

 sends a thread-like growth the entire length of the silk, 

 (Productive Farm Crops.) 



The pollen 

 . 

 grains maV then U6- 



, , , i , 



velop a long, thread- 

 like growth which reaches the ovules within the base of the pistil. 

 When the pollen growth reaches the ovule a fusion of the two 

 takes place. This may be termed the fertilization of the ovules. 

 Seed cannot properly develop until such fertilization takes place. 

 Flowers which pollinize their own pistils are probably not so 

 common among the cultivated plants as in wild ones. Self-pollin- 



